optimize so we don't end up calling data property three times

Author: andyshinn

bridger/mqtt.py

@@ -59,9 +59,11 @@ def on_message(self, client, userdata, message):
             pb_processor = PBPacketProcessor(self.influx_client, service_envelope)
             set_user({"id": getattr(service_envelope.packet, "from")})
 
-            if pb_processor.data:
-                logger.bind(envelope_id=packet_id).debug(f"Trying to write data: {pb_processor.data}")
-                pb_processor.write_point(pb_processor.data)
+            data = pb_processor.data
+
+            if data:
+                logger.bind(envelope_id=packet_id).debug(f"Trying to write data: {data}")
+                pb_processor.write_point(data)
             else:
                 logger.bind(envelope_id=packet_id).debug("No data to write")